Automotive vehicle framing system

ABSTRACT

A vehicle framing system for framing an automotive vehicle body from a plurality of separate body components wherein the body components each include a reference surface. The system includes an assembly station having spaced-apart frame members positioned so that, when a vehicle carrier supporting the vehicle body components is positioned at the assembly station, the frame members extend along opposite sides of the vehicle carrier. At least two docking stations are secured to each frame member at predetermined locations. A robot mounts its associated tool arm with a docking station. At least one set of reference block and framing clamp is secured to each tool arm and these framing clamps maintain the reference surfaces of the vehicle body components against the reference blocks to hold the vehicle components at a predetermined position relative to each other. After each robot positions each associated tool arm with the docking station, the robot disengages from the tool arm and then welds the body components together by a welding gun carried by the robots.

BACKGROUND OF THE INVENTION

I. Field of the Invention

The present invention relates to an automotive framing system, or anyother geometry station, for accurately positioning vehicle bodycomponents relative to each other prior to securing the vehicle bodycomponents together.

II. Description of the Prior Art

In the manufacture of automotive vehicles, a conveyor system typicallytransports a body preassembly sequentially along a conveyor line. Suchbody preassemblies supported by a vehicle carrier comprise various bodycomponents, such as an underbody, front structure, body sides, headers,etc., which are loosely attached to each other in their approximatefinal assembly position relative to each other.

In order to fixedly secure the body components together, it isimperative that the body components be precisely positioned relative toeach other to freeze their geometry by “tack welds” performed in thisframing station, prior to a “respot” of the whole body in order toprovide its final strength. To accomplish such precision positioning ofthe body components, there have been previously known automotive framingsystems.

In one prior art automotive framing system, a gantry is positioned abovethe assembly station at a midpoint of the conveyor line. The gantryincludes swing arms which are movable between a raised and a loweredposition. In their raised position, the swing arms are positioned awayfrom the body preassembly which enables the next preassembly to be movedby the conveyor system into the assembly station. Conversely, in theirengaged position, the arms swing downwardly approaching “damp units”supporting reference blocks and clamps to engage predetermined referencesurfaces or location points of the various vehicle body components, andclamp the body components together at a predetermined position relativeto each other. With the body components clamped together, roboticwelders or the like extend through openings in the reference frame andare used to fixedly secure the body components together by “tack welds”.

In still a further type of previously known automotive framing system, areference frame is positioned around the body preassembly when thepreassembly is positioned at the assembly station. In this type ofpreviously known automotive framing system, pivoting or sliding unitsconnected to the reference frame and supporting reference blocks andclamps extend into the interior of the automotive vehicle bodycomponents to engage the reference surfaces of the body components, andlock the body components together at a predetermined position relativeto each other prior to welding.

In still a further type of previously known automotive framing system, aside gate is positioned along each side of the assembly station. Theseside gates are movable between a retracted position, in which the gatesare positioned laterally outside the assembly station to permit the bodypreassembly to be moved into the assembly station, and an assemblyposition in which the gates are positioned along each outer side of thebody preassembly. Pivoting or siding units mounted onto the gates andsupporting clamping assemblies then extend into the vehicle bodycomponents to secure the body components in the desired predeterminedposition relative to each other. Thereafter, robotic welders extendthrough openings in the gate, into the vehicle and “tack weld” thevehicle body components together.

All of these previously known automotive framing systems, however,suffer from a number of common disadvantages. First, the wide areacovered by the same tool structure, i.e. the gate or swing arm, does notenable a common approaching trajectory for the tool structure in whichall the reference blocks and clamp units will remain stationary on thetool structure, and the clamps of simple design. Further, to remainquasi-standard, the gates, frames, or swing arms supporting the pivotingor sliding units holding the reference blocks and clamping units willstay positioned remotely around the exterior of the body preassembly.Since the clamping surfaces on the body components are frequentlycontained within the interior of the body preassembly, these previouslyknown framing systems necessarily required complex, articulated clampingassemblies which must extend into the interior of the body preassemblyin order to clamp the body components at their desired position relativeto each other. Such clamping assemblies are oftentimes necessarilyarticulated relative to their gate or reference frame. As such, theseclamping assemblies are both expensive to manufacture and subject towear after prolonged use. Such wear adversely affects the accuracy ofthe overall framing system.

A still further disadvantage of these previously known framing systemsis that, after the body preassembly has been moved into the assemblystation and clamped at the desired position relative to each other, itis necessary for robotic welders to then extend through openings ineither the gate or the reference frame in order to weld the bodycomponents together. Due to interference between the robotic welders andeither the gate or reference frame, the use of complex andtime-consuming robot trajectories, and thus expensive roboticengineering study, has been required.

A still further disadvantage of these previously known framing systemsis that it is necessary to use a different reference frame or adifferent gate even for slightly different vehicle body styles. Sincemultiple body styles are oftentimes assembled together at a singleassembly station, it has been previously necessary to move eitherdifferent reference frames or different gates to the assembly station inorder to accommodate the different vehicle body styles. Since thesepreviously known reference frames and gates are massive in constructionand require a long design and fabrication time, they are expensive andmay delay the time to put a new vehicle on the market. Furthermore,these systems require a large footprint on the shop floor to store theunused set of tools.

Recently, a new generation of framing system has been developed to takeadvantage of the low cost, mass-produced robots. All these framers tryto reproduce the exact same tool change movement previously achievedwith a dedicated piece of machinery, but by using a dedicated high loadcapacity robot. The tooling used corresponds to the previous gates orframes, but is more simply built with lighter structure, material andcomponents. There is, of course, an initial saving achieved on the toolhanding system, but because the tooling remains large and difficult tohandle, the full agility of the robot cannot be exploited. Furthermore,the tooling still requires a lot of pivoting or sliding units to bringsome movable reference blocks into contact with their working surface,thus increasing the complexity of the tooling, its weight, compliance,cost, reliability and cycle time.

SUMMARY OF THE PRESENT INVENTION

The present invention provides an automotive framing system for avehicle body which overcomes all of the above-mentioned disadvantages ofthe previously known devices by splitting the traditional large toolframe in a set of elementary tool arms with which the robot can developits full agility to set in position.

In brief, the vehicle framing system of the present invention comprisesan assembly station having spaced-apart frame members. A vehicle carrierwhich supports the vehicle body components in a preassembled conditionis then moved into the assembly station by a conventional conveyor.

Depending on the body carrier type, i.e. a skid or a geometry pallet,these spaced-apart frame members can be vertically movable butpreferably stationary.

At least two docking stations are secured to each frame member atpredetermined positions along the frame member. A tool arm is associatedwith each docking station and each tool arm includes at least one set ofreference blocks or locating pins and its clamp designed to engage areference surface on one of the vehicle body components to secure thevehicle body components at predetermined positions relative to eachother.

A robot is associated with each tool arm and will preferably carry bothits welding gun and its associated tool arm to avoid lost time inswitching one for the other. The robot moves each tool arm between anassembly position and a vehicle loading position where other tool armsdedicated to other vehicle types are stored.

During the body loading operation, the proper tool arm is selected froma tool arm storage support 27 (FIG. 1) and engaged by the robot. As soonas the new loose-mounted body preassembly is positioned in the framingstation, each robot manipulates its tool arm into the body frame thusbringing the stationary reference block into contact with thecorresponding location surface. Once in the exact assembly position,each tool arm abuts against its associated docking station so that eachtool arm is positioned at the assembly station at a predeterminedposition relative to the frame members at the assembly station. Then atool arm clamp mounted on each docking station clamps the tool arm toits associated docking position at a predetermined position and a mediaquick coupling provides pressurized air and electric connections toenergize the clamps or any other air cylinder or proximity switches.

Once the tool arms are secured to their associated docking stations,each robot disengages from its associated tool arm, while at the sametime all the clamping sequence is achieved. Thereafter, a welder carriedby at least one of the robots extends into the body vehicle preassemblyin order to fixedly secure the body components together at theirpredetermined position relative to each other thus completing the bodyassembly.

After the body components are welded together, the clamps are releasedand each robot reengages with its associated tool arm. Thereafter, thetool arm clamps disengage thus releasing the tool arms from theirassociated docking stations. The robots then move the tool armslaterally outwardly to their vehicle loading position, and depending onthe next vehicle to frame or a specific process, it may either keep thesame tool arm or drop it to “respot” the current vehicle, or take a newtool arm matching the new vehicle type. Thereafter, the now assembledvehicle body assembly is moved by the conveyor out of the assemblystation while a new vehicle carrier supporting a new body preassembly ismoved into the assembly station and the above process is repeated.

A primary advantage of the framing system of the present invention isthat the robots are able to manipulate the tool arms so that a portionof one or more of the tool arms extend into the body preassembly andclosely adjacent the body component reference surfaces. As such,relatively inexpensive clamping assemblies carried by each tool arm areemployed to not only rapidly, but also accurately, position the vehiclebody components together in preparation for final assembly. Sincerelatively simple clamping assemblies are used to position the vehiclebody components, inaccuracies caused by wear and/or design of thepreviously known articulated clamps are avoided and welding robotaccessibility is maximized.

A still further advantage of the automotive framing system of thepresent invention is that different tool arms may be easily engaged andmanipulated by the robots in order to accommodate different body styles.Furthermore, in case of robot interference or crash or other tool armmalfunction, only a simple fraction of the tooling will need to be fixedand geometrically recalibrated.

Since all of the robots installed are fully utilized in both thehandling and welding processes, the extra cost and additional footprintand volume requirement next to the body to frame of the previous systemswhich used dedicated robots for handling is avoided.

The present invention allows up to four medium capacity welding robotsper side for a pure floor-mounted configuration and, if necessary, fourto six additional robots mounted on a balcony, reducing the overallcycle time for a given number of tack-welds to be performed.

BRIEF DESCRIPTION OF THE DRAWING

A better understanding of the present invention will be had uponreference to the following detailed description, when read inconjunction with the accompanying drawing, wherein like referencecharacters refer to like parts throughout the several views, and inwhich:

FIG. 1 is a top plan view illustrating a preferred embodiment of thepresent invention;

FIG. 2 is an elevational view illustrating a preferred embodiment of thepresent invention and with parts removed for clarity;

FIG. 3 is a sectional fragmentary view illustrating the docking of atool arm with its associated docking station;

FIG. 4 is a fragmentary elevational view illustrating one tool arm and aportion of its associated robot;

FIG. 5 is a view similar to FIG. 3, but illustrating the tool arm in aconnected position with its associated docking station;

FIG. 6 is a view similar to FIG. 4, but illustrating the robotic armdisengaged from its associated tool arm; and

FIG. 7 is a diagrammatic end view illustrating the introduction of thetool arm in contact with the body to be framed, and its finalpositioning on the docking station.

DETAILED DESCRIPTION OF A PREFERRED EMBODIMENT OF THE PRESENT INVENTION

With reference first to FIG. 1, a preferred embodiment of the automotiveframing system 10 of the present invention is shown for use with amanufacturing line for automotive vehicles. As used in this patent, theterm “framing system” encompasses not only the vehicle frame of anautomotive vehicle, but also any application where accurate positioningof two or more body components is desired. For example, such a framingsystem would also include fender setting, roof setting, door setting, aswell as other vehicle body components than the vehicle frame. Anelongated conveyor 12, illustrated only diagrammatically, sequentiallyconveys automotive body vehicle carriers 14 to an assembly station 16.Any conventional type of conveyor 12 may be utilized to convey thevehicle carrier 14 to the assembly station 16.

As best shown in FIG. 2, each vehicle body carrier 14 supports a bodypreassembly 18 comprising a plurality of body vehicle components 20. Thebody vehicle components 20 are only loosely fastened together in theirapproximate final assembly position by restraining tags, also known astoy tabs, or other conventional means (not shown). Furthermore, thevehicle body carrier 14 is conventionally known as a skid or a geometrypallet in the automotive industry.

With reference now particularly to FIG. 2, the assembly station 16 isshown in greater detail and comprises a pair of spaced apart framemembers 22 which extend along opposite sides of the vehicle body carrier14 and thus along opposite sides of the body preassembly 18. Preferably,crossbeams 24 extend laterally between the frame members 22 to lock theframe members 22 together in a predetermined fixed position.

Still referring to FIG. 2, at least two and preferably three or fourdocking stations 26 are provided along each side of the assembly station16. Each docking station 26 is fixedly secured to the frame members 22so that the position of each docking station 26 is fixed relative to theframe member 22 and thus relative to the assembly station 16.

As best shown in FIGS. 2 and 3, each docking station 26 includes atleast one and preferably three locator pins 28 so that each locator pin28 is positioned at an apex of a triangular surface 30, preferablyoriented at 45 degrees from the horizontal on the docking station 26. Asbest shown in FIG. 3, each locator pin 28 is preferably frusto-conicalin shape with a preferred conicity angle of 90 degrees, and the pins 28are fixedly secured to their associated docking stations 26.

Each docking station 26 also includes a media quick coupling 58 (FIGS. 3and 5) which provides pressurized air and electric signals to theassociated clamp arm in order to energize the framing clamps 64 as wellas other air cylinder or proximity switches.

With reference now particularly to FIGS. 2 and 4, the framing systemfurther includes a plurality of tool arms 40 which, as will be shortlydescribed, selectively clamp the vehicle body components 20 together ata predetermined position relative to each other prior to final assembly.It will be understood, of course, that the precise configuration of eachtool arm 40 will vary depending upon the type of vehicle assembled atthe assembly station 16. Consequently, the tool arms 40 illustrated inthe drawing are for illustration purposes only.

With reference then to FIGS. 2–4, the tool arm 40 includes a main body42 which is constructed of any rigid but light material, such asthin-walled steel, aluminum or magnesium alloy. A locating surface 44(FIG. 3) at one end of the tool arm body 42 includes at least one andpreferably three locating sockets 46. The locating sockets 46 arecomplementary in shape and number to the locating pins 28. Furthermore,the locating sockets 46 are positioned on the surface 44 of the tool arm40 such that one socket 46 corresponds to and is aligned with onelocating pin 28 on the docking station 26. Preferably, the shape of thetool arm main body 42 will have a tetrahedral profile, with a triangularbasis matching the locating socket outer pattern.

A robotic arm 50 (FIG. 4) of a robot 52 (FIG. 1) is associated with eachtool arm 40. Furthermore, the robotic arm 50 is selectively secured toits associated tool arm 40 by a conventional robotic coupling 51 so thatthe robotic arm 50 moves its associated tool arm 40 between retracted avehicle loading position and an assembly position. In the vehicleloading position, the robotic arm 50 moves its associated tool arm 40laterally outwardly from the assembly station 16 to enable a new bodypreassembly to be moved into the assembly station. Conversely, in itsassembly position, the robotic arm 50 selectively moves its associatedtool arm 40 so that the reference blocks 60, e.g. locating pins,supported by the tool arm enter in contact with their matching surfacesonto the body shell, and then the locating sockets 46 engage thelocating pins 28 as shown in FIG. 5. A conventional clamp assembly 54mounted to the docking station 26 then engages a clamp pin 56 on thetool arm 40 to detachably lock the tool arm 40 to its associated dockingstation 26 at a predetermined and fixed position relative to theassembly station frame members 22. Thereafter, the robotic arm 50disengages from its associated tool arm 40 by unlocking the roboticcoupling 51 as shown in FIG. 6.

Referring now particularly to FIGS. 2 and 4, at least one, and moretypically two or more, framing clamps 64 are secured to each tool arm40. These framing clamps 64, once the robotic arm 50 has positioned thereference blocks 60 of its associated tool arm 40 onto the body shell,and its associated tool arm 40 on the docking station 26, engage acrossclamping surfaces 62 on the body components 20. Upon activation of theframing clamps 64, the framing clamps 64 secure the body components 18against the reference block 60 at a predetermined position relative tothe assembly station frame member 22 and thus relative to each other.When all of the framing clamps 64 engage their respective clampingsurfaces on the body components 20, the body preassembly 18 is ready tobe secured or welded together.

As best shown in FIG. 6, after the robotic arm 50 has positioned itsassociated tool arm 40 at its associated docking station 26, and oncethe docking station lock 54 (FIG. 5) is engaged, the robotic arm 50disengages from its associated tool arm body 42 by unlocking the roboticcoupling 52. Thereafter, a welding gun 70 attached to the robotic arm 50is then manipulated by the robotic arm 50 into the body preassembly 18.Upon activation of the welding gun 70, the welding gun 70 secures thebody components 20 together thus completing the automotive bodyassembly.

It will be understood, of course, that although the body components 20are typically secured together by welding, other types of attachingmeans may alternatively be used without deviation from either the scopeor spirit of the present invention.

After the vehicle body components 12 have been welded or otherwisesecured together by the robots 50 manipulating the welding guns 70 orother attachment means, each robotic arm 50 then reengages with itsassociated tool arm 40 by locking the tool arm 40 to the robotic arm 50by the coupling 51 as shown in FIG. 4. In the meantime, all the framingclamps 64 are released. Thereafter, the tool arm clamp assembly 54 (FIG.5) is actuated to its unlocked position thus enabling the tool arm 40 todisengage from its associated docking station 26. The framing clamps 64are also opened, so that each robotic arm 50 is then able to move itsassociated tool arm 40 from the assembly position to a vehicle loadingposition at a position spaced laterally outwardly from the framingstation 16. In the case of a new vehicle model to be framed, the robotwill drop the previous tool arm 40 in its tool arm storage 27 (FIG. 1)and pick a new one suitable for the new model.

After the tool arms 40 are moved to their vehicle loading position, thenow assembled automotive body is moved by the conveyor 12 out of theassembly station 16, a new vehicle carrier 14 with its body preassembly18 is moved into the assembly station 16 and the above process isrepeated.

With reference now to FIG. 7, an important advantage of the presentinvention is that each robotic arm 50 is able to manipulate portions ofits associated tool arm 40 into the interior of the body preassembly 18so that stationary reference blocks 60 are positioned closely adjacentthe reference surfaces on the body components 20. For example, as shownin FIG. 7, the robotic arm 50 may be used to manipulate its associatedtool arm 40 to move sections of the tool arm 40 through relatively smallopenings 68 of the body preassembly 18 prior to attaching the tool arm40 to its docking station 26 as shown in solid line. This, in turn,permits inexpensive and accurate stationary reference block 60 and rapidacting clamps 64 to be used to secure the body components 20 together attheir desired position prior to assembly.

A still further advantage of the present invention is that differentvehicle body styles may be assembled at the same assembly station 16 andusing the same robots 52. More specifically, since the robotic arms 50of the robots 52 selectively engage and disengage from their associatedtool arms 40, the robotic arms 50 may also selectively engage differenttool arms 40 in order to accommodate different automotive body styles.As such, by merely selectively engaging and disengaging with differenttool arms 40, different body styles may be easily accommodated andassembled at the same assembly station 16. Because of the modularity ofthe tool set used, if the design of two different bodies presents somecommonality, such as a front block, only a fraction of the tool set canbe changed to frame this different body.

Having described my invention, many modifications thereto will becomeapparent to those skilled in the art to which it pertains withoutdeviation from the spirit of the invention as defined by the scope ofthe appended claims.

1. A vehicle framing system for framing a vehicle body from a pluralityof separate body components, at least one of the vehicle body componentshaving a reference surface, comprising: an assembly station havingspaced-apart frame members; a vehicle carrier which supports the vehiclebody components in a preassembled condition at said assembly station; atleast two docking stations secured to each frame member at predeterminedpositions; a tool arm associated with each docking station; a robotassociated with each tool arm for moving said tool arm between anassembly position in which each said tool arm abuts against itsassociated docking station at a predetermined position, and a vehicleloading position in which each tool arm is disengaged from itsassociated docking station; a tool arm clamp mounted to each dockingstation which clamps said tool arm to its associated docking station atsaid predetermined position when said tool arm is in said assemblyposition, said tool arm clamp forming the sole means for removablysecuring each said tool arm to its associated docking station; and aframing clamp having a reference block secured to each tool arm andmovable between a clamped and an unclamped position, wherein saidclamped position of each framing clamp maintains its reference block incontact with the at least one reference surface on the vehicle bodycomponent to thereby maintain said vehicle body components at apredetermined position relative to each other.
 2. The invention asdefined in claim 1 and comprising means for selectively detachablyconnecting each robot with its associated tool arm.
 3. The invention asdefined in claim 1 and comprising a welding gun connected to at leastone of said robots.
 4. The invention as defined in claim 3 wherein thewelding robots are sized to carry and dynamically move their associatedtool arms without having to disconnect from their welding guns.
 5. Theinvention as defined in claim 1 wherein, with said tool arms at theirrespective assembly positions, at least a portion of at least one toolarm extends into an interior of the vehicle body components.
 6. Theinvention as defined in claim 1 wherein each docking station includesthree spaced locator pins, each locator pin having a predefined locatingsurface, and wherein each tool arm includes three locator sockets, eachtool arm locator socket having a locating surface complementary to andaligned with said docking station locating pins.
 7. The invention asdefined in claim 6 wherein said docking station locator pins arefrusto-conical in shape.
 8. The invention as defined in claim 6 whereinsaid docking station locator pins are positioned at the apices of atriangle.
 9. The invention as defined in claim 8 wherein said locatorpins are in a plan preferably oriented at 45 degrees from thehorizontal.
 10. The invention as defined in claim 8 wherein said toolarm clamp is aligned with the centroid of said triangle.
 11. Theinvention as defined in claim 10 wherein said tool arm clamp remainsclamped in case of power outage (type activate for release).
 12. Theinvention as defined in claim 6 wherein frusto-conical locator pins havea preferred conicity angle of 90 degrees.
 13. The invention as definedin claim 6 and comprising a media quick connector for pressurized airand electric communication in between the docking station and tool arm,said media being used to activate and control said inboard framing clampand locating pin cylinder.
 14. The invention as defined in claim 1wherein the tool arm main body has a tetrahedral shape with a triangularbasis matching the pattern of the locating socket outer perimeter. 15.The invention as defined in claim 1 and comprising a conveyor whichmoves said vehicle carrier to said framing station.
 16. The invention asdefined in claim 1 wherein said robot includes a coupler whichselectively engages its associated tool arm.